Patents by Inventor Toshifumi Kakinuma

Toshifumi Kakinuma has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Electromagnetic directional control valve
    Patent number: 5101856
    Abstract: A spool of a valve main body is switched and driven by exciting a solenoid coil by supplying a DC or AC voltage. An intensity of the magnetism generated by the excitation of the solenoid coil is detected by a magnetic sensor. When a predetermined sensor output is obtained, an indicator lamp is lit to indicate that the spool has operated correctly. The intensity of the magnetism due to the DC excitation is detected by magnetoresistive devices. The intensity of magnetism due to the AC excitation is detected by a pickup coil or a current transformer.
    Type: Grant
    Filed: June 28, 1990
    Date of Patent: April 7, 1992
    Assignee: Tokyo Keiki Company Ltd.
    Inventors: Toshifumi Kakinuma, Kiyoshi Hayashi
  • Electromagnetic directional control valve
    Patent number: 4953590
    Abstract: A spool of a valve main body is switched and driven by exciting a solenoid coil by supplying a DC or AC voltage. An intensity of the magnetism generated by the excitation of the solenoid coil is detected by a magnetic sensor. When a predetermined sensor output is obtained, an indicator lamp is lit to indicate that the spool has operated correctly. The intensity of the magnetism due to the DC excitation is detected by magnetoresistive devices. The intensity of magnetism due to the AC excitation is detected by a pickup coil or a current transformer.
    Type: Grant
    Filed: March 31, 1989
    Date of Patent: September 4, 1990
    Assignee: Tokyo Keiki Company Ltd.
    Inventors: Toshifumi Kakinuma, Kiyoshi Hayashi